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| United States Patent |
5,350,724
|
|
Martin
|
September 27, 1994
|
Polyolefin polymerization process, process of producing catalyst, and
catalyst
Abstract
A process for preparing a polymerization catalyst useful for the
polymerization of olefins is provided comprising contacting a magnesium
compound and a transition metal halide to form a solid product; contacting
the solid product with an organoaluminum halide to form a first catalyst
component, and contacting the first catalyst component with an activating
agent to form a catalyst. Other aspects of the invention provide a
catalyst prepared by the above described method and a polymerization
process employing the thus prepared catalyst.
| Inventors:
|
Martin; Joel L. (Bartlesville, OK)
|
| Assignee:
|
Phillips Petroleum Company (Bartlesville, OK)
|
| Appl. No.:
|
058167 |
| Filed:
|
May 4, 1993 |
| Current U.S. Class: |
502/110; 502/104; 502/111; 502/113; 502/115; 502/119; 526/151 |
| Intern'l Class: |
B01J 031/00; C08F 004/64 |
| Field of Search: |
502/104,110,111,113,115,119
|
References Cited
U.S. Patent Documents
| 4244838 | Jan., 1981 | Gessell | 252/429.
|
| 4400302 | Aug., 1983 | Goodall et al. | 502/121.
|
| 4401589 | Aug., 1983 | Kioka et al. | 252/429.
|
| 4410451 | Oct., 1983 | Dietz et al. | 502/110.
|
| 4537870 | Aug., 1985 | Hawley | 502/111.
|
| 4551439 | Nov., 1985 | Harada et al. | 502/107.
|
| 4742139 | May., 1988 | Kioka et al. | 526/125.
|
| 4980330 | Dec., 1990 | Marchand et al. | 502/125.
|
Primary Examiner: Pal; Asok
Attorney, Agent or Firm: Michel; Marianne H.
Claims
That which is claimed is:
1. A process for preparing a polymerization catalyst comprising
(1) contacting a magnesium compound, a 4-phenylphenol, and titanium
tetrachloride to form a solid product,
wherein said magnesium compound is a dialkylmagnesium compound wherein each
alkyl group contains 1 to 12 carbon atoms;
(2) contacting said solid product and an organoaluminum halide to form a
first catalyst component,
wherein said organoaluminum halide contains at least one hydrocarbyl
radical selected from hydrocarbyl radicals containing 1 to 12 carbon atoms
per radical; and
(3) contacting said first catalyst component and an activating agent to
form said catalyst,
wherein said activating agent is titanium tetrachloride, silicon
tetrachloride, C.sub.6 H.sub.5 SiCl.sub.3, or mixtures thereof.
2. A process according to claim 1 wherein said magnesium compound is a
dialkylmagnesium compound wherein each alkyl group contains 1 to 6 carbon
atoms.
3. A process according to claim 2 wherein said magnesium compound is a
dibutylmagnesium compound.
4. A process according to claim 1 wherein said phenol and said magnesium
compound are contacted prior to contacting with said titanium
tetrachloride.
5. A process according to claim 1 wherein said organoaluminum halide is
ethylaluminum sesquichloride.
6. A process according to claim 1 wherein the molar ratio of said titanium
tetrachloride in said solid product to said magnesium compound is within
the range of about 0.1: to about 10:1;
wherein the molar ratio of said titanium tetrachloride in said first
catalyst component to said organoaluminum halide is within the range of
about 0.1:1 to about 10:1; and
wherein the weight ratio of said activating agent to said first catalyst
component is within the range of about 0.1:1 to about 100:1.
7. A catalyst produced according to the process of claim 1.
8. A process for preparing a polymerization catalyst comprising:
(1) contacting dibutylmagnesium, a 4-phenylphenol, and then titanium
tetrachloride to form a solid product;
(2) contacting said solid product and ethylaluminum sesquichloride to form
a first catalyst component; and
(3) contacting said first catalyst component and an activating agent to
form said catalyst,
wherein said activating agent is titanium tetrachloride, silicon
tetrachloride, C.sub.6 H.sub.5 SiCl.sub.3, or mixtures thereof.
9. A process according to claim 8 wherein the molar ratio of said titanium
tetrachloride in said solid product to said dibutylmagnesium is within the
range of 0.2:1 to 2:1;
wherein the molar ratio of said titanium tetrachloride in said first
catalyst component to said ethylaluminum sesquichloride is within the
range of 0.1:1 to 3:1; and
wherein the weight ratio of said activating agent to said catalyst is
within the range of 0.5:1 to 75:1.
10. A catalyst produced according to the process of claim 8.
Description
BACKGROUND OF THE INVENTION
This invention relates to transition metal catalysts and methods for their
production and use in the polymerization of olefins.
In the production of polyolefins, such as for example polyethylene,
polypropylene, ethylene-butene copolymers, polymethylpentene, etc., an
important aspect of the various processes and catalysts used to produce
such polymers is the productivity. By productivity is meant the amount or
yield of solid polymer that is obtained by employing a given quantity of
catalyst. If the productivity is high enough, then the amount of catalyst
residues contained in the polymer is low enough that the presence of the
catalyst residues does not significantly affect the properties of the
polymer and the polymer does not require additional processing to remove
the catalyst residues. As those skilled in the art are aware, removal of
catalyst residues from polymer is an expensive process and it is very
desirable to employ a catalyst which provides sufficient productivity so
that catalyst residue removal is not necessary. High productivities are
also desirable in order to minimize catalyst costs.
It is therefore desirable to develop catalysts which provide relatively
high catalyst productivity.
SUMMARY OF THE INVENTION
Objects of the present invention are, therefore, to provide an olefin
polymerization catalyst with a relatively high productivity and also a
process for producing such a catalyst.
In accordance with one aspect of the present invention, a process to
prepare a catalyst is provided which comprises (1) contacting a magnesium
compound and a transition metal halide to form a solid product, (2)
contacting the solid product with an organoaluminum halide to form a first
catalyst component, and (3) contacting the first catalyst component with
an activating agent to form the catalyst. The magnesium compound contains
at least one hydrocarbyl radical. The transition metal halide is a halide
of a transition metal selected form Group 4 and Group 5 of the Periodic
Table. As used herein by the term "Periodic Table" is meant the Periodic
Table of the Elements shown as the new IUPAC form on the inside front
cover of Handbook of Chemistry and Physics, 70th Edition, CRC Press, Inc.
(1990).
In accordance with other aspects of the invention a catalyst produced by
the above described process and a polymerization process employing the
catalyst are provided.
DETAILED DESCRIPTION OF THE INVENTION
The magnesium compound contains a t leas t one hydrocarbyl radical, wherein
the hydrocarbyl radical is selected from alkyl, cycloalkyl, aryl, alkaryl,
and aralkyl hydrocarbyl radicals containing 1 to 20 carbon atoms per
radical.
Suitable magnesium compounds include dihydrocarbylmagnesium compounds and
Grignard reagents. Examples of suitable magnesium compounds include,
dimethylmagnesium, diethylmagnesium, dibutylmagnesium,
n-butyl-sec-butylmagnesium, dipentylmagnesium, didodecylmagnesium,
diphenylmagnesium, dibenzylmagnesium, dicyclohexylmagnesium,
di(4-t-butylphenyl)magnesium, methylmagnesium chloride, ethylmagnesium
chloride, isopropylmagnesium chloride, tert-butylmagnesium chloride,
n-butylmagnesium chloride, sec-butylmagnesium chloride, pentylmagnesium
chloride, dodecylmagnesium chloride, phenylmagnesium chloride,
benzylmagnesium chloride, cyclohexylmagnesium chloride, methylmagnesium
bromide, ethylmagnesium bromide, n-butylmagnesium bromide,
sec-butylmagnesium bromide, tert-butylmagnesium bromide, pentylmagnesium
bromide, dodecylmagnesium bromide, phenylmagnesium bromide,
benzylmagnesium bromide, cyclohexylmagnesium bromide, methylmagnesium
iodide, ethylmagnesium iodide, n-butylmagnesium iodide, sec-butylmagnesium
iodide, tert-butylmagnesium iodide, pentylmagnesium iodide,
dodecylmagnesium iodide, phenylmagnesium iodide, benzylmagnesium iodide,
cyclohexylmagnesium iodide, and mixtures thereof. The presently preferred
compounds are dialkylmagnesium compounds in which each alkyl group
contains 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms. The
most preferred compounds due to availability and performance are
dibutylmagnesium compounds.
The transition metal halide is a halide of a transition metal selected from
Group 4 and Group 5 metals of the Periodic Table. Titanium halides are the
preferred compounds and titanium tetrachloride is especially preferred
because it produces excellent, results and is readily available.
The molar ratio of the transition metal halide to the magnesium compound
can be selected over a relatively broad range. Generally the molar ratio
is within the range of about 0.1:1 to about 10:, preferably from 0.2:1 to
2:1.
The magnesium compound and the transition metal halide, can be reacted in
the presence of a liquid diluent or solvent, or when at least one of the
reagents is in the liquid state during the reaction, the use of diluent
can be omitted. The magnesium compound and the transition metal halide are
normally mixed together in a suitable dry (essential absence of water)
diluent or solvent, which is essentially inert to these components and the
product produced. By the term "inert" is meant that the diluent does not
chemically react with the dissolved components such as to interfere with
the formation of the product or the stability of the product once it is
formed. Such diluents include, for example, n-pentane, n-hexane,
n-heptane, methylcyclohexane, toluene, and xylenes. Aromatic solvents are
preferred because the solubility of the magnesium compound and the
transition metal halide is higher in aromatic solvents as compared to
aliphatic solvents, particularly at low temperatures. Xylenes are most
preferred.
Generally the amount of solvent or diluent employed can be selected over a
broad range. Usually the amount of solvent or diluent is within the range
of about 1 to about 100 cc per gram of magnesium compound, preferably from
20 to 100 cc per gram.
Temperatures for contacting the magnesium compound and the transition metal
halide are generally within the range of from about 0.degree. C. to about
150.degree. C. and preferably from 10.degree. C. to 150.degree. C. The
contacting temperatures employed could be higher if the pressure employed
is above atmospheric pressure.
The pressure employed during contacting of the magnesium compound and the
transition metal halide does not appear to be a significant parameter and
can vary broadly. Generally the pressure is within the range of about 0.1
to about 5.0 MPa.
Generally, the time required for contacting the magnesium compound and the
transition metal halide is within the range of about 5 minutes to about 10
hours, although in most instances a time within the range of 15 minutes to
3 hours is sufficient. Following the contacting operation, the resulting
solution can be filtered to remove any undissolved material or extraneous
solid, if desired.
According to a preferred embodiment, an alcohol is also employed in
preparing the solid product in step (1). Alcohols that can be employed
include either monohydroxy or polyhydroxy alcohols containing from 1 to 20
carbon atoms, preferably from 1 to 16 carbon atoms. The alcohol can be
aliphatic or aromatic alcohols. The aliphatic alcohols can be saturated or
unsaturated. Suitable alcohols include methanol, ethanol,
2,2,2-trifluoroethanol, isopropanol, n-butanol, sec-butanol, tert-butanol,
1-pentanol, 2-pentanol, 1-hexanol, 2-hexanol, 2-ethylhexanol, 1-octanol,
decanol, dodecanol, hexadecanol, cyclohexanol, diols such as
1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol,
1,2-hexanediol, 1,2-decanediol, 1,2-octanediol, and 1,10-decanediol,
glycerols, benzyl alcohol, methylbenzyl alcohol, isopropylbenzyl alcohol,
substituted and unsubstituted phenols, and mixtures thereof.
Preferably, the alcohol employed in preparing the solid product is a
substituted or unsubstituted phenol containing from 6 to 16 carbon atoms.
Typical examples include phenol, 2-methylphenol, 3-methylphenol,
4-methylphenol, 4-phenylphenol, 2,6-di-t-butyl-4-methylphenol,
2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-bromophenol,
3-bromophenol, 4-bromophenol, 2-fluorophenol, 3-fluorophenol,
4-fluorophenol, 4-sec-butylphenol, 4-ethylphenol, 4-methoxyphenol, and
mixtures thereof. Of those phenols, 4-phenylphenol is the most preferred.
The molar ratio of the alcohol employed relative to the transition metal
halide can vary over a relatively broad range. Generally the molar ratio
is within a range of from about 0.1:1 to about 10:1 and preferably from
0.2:1 to 5:1. In a particularly preferred embodiment, the alcohol and the
magnesium compound are contacted prior to contacting with the transition
metal compound when forming the solid product.
The organoaluminum halide contains at least one hydrocarbyl radical,
wherein the hydrocarbyl radical is selected from hydrocarbyl radicals
selected from alkyl, cycloalkyl, aryl, alkaryl, and aralkyl hydrocarbon
radicals containing 1 to 20 carbon atoms per radical, preferably from 1 to
16 carbon atoms, and more preferably from 1 to 12 carbon atoms. Typical
examples include methylaluminum dibromide, ethylaluminum diiodide,
dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum
chloride, diisobutylaluminum chloride, dodecylaluminum dibromide,
dimethylaluminum bromide, methyl-p-propylaluminum bromide,
di-n-octylaluminum bromide, dicyclohexylaluminum bromide,
di-n-decylaluminum chloride, ethylisobutylaluminum chloride,
diphenylaluminum chloride, dieicosylaluminum chloride, di-n-propylaluminum
chloride, methylaluminum sesquibromide, ethylaluminum sesquiiodide,
ethylaluminum sesquichloride, and mixtures thereof. Ethylaluminum
sesquichloride is readily available and has been employed with good
results, and is therefore especially preferred.
The molar ratio of the transition metal halide to the organoaluminum halide
can be selected over a relatively broad range. Generally, the molar ratio
is within a range of from about 0.1:1 to about 10:1 and preferably within
a range of 0.1:1 to 3:1.
The contacting of the solid product and the organoaluminum halide can be
carried out either in the presence of a liquid diluent, or when at least
one of the reagents is in the liquid state, in the absence of such
diluent. Preferably, the solid product of step (1) is contacted with a
hydrocarbon solution of the organoaluminum halide. Diluents or solvents
which can be employed in preparing the solid product, as described above,
are also suitable for contacting the solid product and the organoaluminum
halide.
The temperature employed while contacting the solid product and the
organoaluminum halide is about 0.degree. C. to about 150.degree. C.,
preferably within the range of about 10.degree. C. to about 150.degree. C.
The pressure employed while contacting the solid product and the
organoaluminum halide can be selected over a broad range. Generally the
pressure is within the range of about 0.1 to about 5.0 MPa.
The solid product, as contacted with the organoaluminum halide, is
contacted for a sufficient time at the above mentioned temperature,
generally within a range of about 5 minutes to about 10 hours, preferably
from 15 minutes to 3 hours, to insure that contacting of the components is
complete. The slurry can be stirred or agitated during contacting.
Thereafter, the thus produced first catalyst component, can be recovered
from the slurry by filtration or decantation. The first catalyst component
can then be washed with a suitable material, such as a hydrocarbon, to
remove any soluble material which may be present. If the first catalyst
component is decanted, the slurry can be stored under dry nitrogen or the
first catalyst component can be dried and then stored under nitrogen.
The activating agent comprises at least one halogen-containing compound of
an element selected from Groups 4, 5, 14, and 15 of the Periodic Table
capable of adding halogen to the catalyst. Examples of suitable activating
agents include CCl.sub.4, COCl.sub.2, CH.sub.2 Cl.sub.2, SnCl.sub.4,
SiCl.sub.4, SiHCl.sub.3, Si.sub.4 Cl.sub.10, CH.sub.3 SiCl.sub.2 H,
C.sub.2 H.sub.5 SiCl.sub.3 (CH.sub.3)2 SiCl.sub.2, Si.sub.2 OCl.sub.6,
Si(OC.sub.2 H.sub.5)Cl.sub.3, .PHI.SiHCl.sub.2 where .PHI. is a phenyl
radical, .PHI..sub.2 SiCl.sub.2, TiCl.sub.4, TiBr.sub.4, TiI.sub.4,
VCl.sub.4, VOCl.sub.3, ZrCl.sub.4, ZrOCl.sub.3, and acid chlorides having
the formula R'COCl where R' is an aliphatic or aromatic radical,
preferably containing 1 to 20 carbon atoms such as benzoyl chloride and
acetyl chloride, and mixtures thereof, Preferably, the activating agent
comprises chlorine-containing compounds of titanium, silicon, or carbon,
or mixtures thereof, more preferably the activating agent comprises
chlorine-containing compounds of titanium, and most preferably comprises
titanium tetrachloride.
While the weight ratio of the activating agent to the first catalyst
component can be selected over a relatively broad range, generally the
weight ratio is within a range of about 0.1:1 to about 100:1 and
preferably from 0.5:1 to 75:1. Following the treatment of the first
catalyst component with the activating agent, the surplus activating agent
can be removed by washing the solid catalyst with a dry (essential absence
of water) liquid such as a hydrocarbon of the type previously discussed,
n-hexane, or xylene for example. The thus activated catalyst can be stored
under an inert atmosphere such as dry nitrogen.
Generally the reaction of the first catalyst component add the activating
agent can be carried out neat or in a liquid medium in which the
activating agent is soluble. Any suitable diluent can be employed.
Examples include normally liquid hydrocarbons such as n-pentane, n-hexane,
n-heptane, cyclohexane, benzene, chlorobenzene, and xylene.
The temperature employed in contacting the first catalyst component and the
activating agent can be selected over a relatively broad range, generally
in the range of about 0.degree. C. to about 150.degree. C., preferably
10.degree. C. to 150.degree. C .
The pressure employed in contacting the first catalyst component and the
activating agent can be selected over a relatively broad range, generally
the pressure will be in the range of about 0.1 MPA to about 5.0 MPa.
The contacting time of the first catalyst component and the activating
agent can be selected over a broad range and generally is within the range
of about 10 minutes to about 10 hours, preferably from 15 minutes to 3
hours. It is noted that the order of addition is not important and either
component can be added to the other.
A variety of polymerizable compounds are suitable for use in the process of
the present invention. Olefins which can be homopolymerized or
copolymerized with the invention catalysts include aliphatic
mono-1-olefins. While the invention would appear to be suitable for use
with any aliphatic mono-1-olefin, those olefins having from 2 to 18 carbon
atoms are most often used.
The present catalysts are particularly useful for the polymerization of
4-methyl-1-pantene and are especially well suited providing high
productivity.
While it may not be necessary in all instances to employ a cocatalyst with
the catalyst of the present invention, the use of cocatalysts is
recommended for best results . The cocatalysts suitable for use in
accordance with the invention can be selected from among the hydrides and
organometallic compounds of metals of Groups 1, 2, 12, and 13 of the
Periodic Table. Some typical examples include lithium alkyls, dialkyl zinc
compounds, and organoaluminum compounds. Of the organometallic
cocatalysts, organoaluminum compounds are preferred. The organoaluminum
cocatalysts are compounds containing at least one hydrocarbyl radical
individually selected from hydrocarbyl radicals containing 1 to 20 carbon
atoms per radical. Typical examples include, trimethylaluminum,
triethylaluminum, triisopropylaluminum, tridecylaluminum,
triesosylaluminum, tricyclohexylaluminum, triphenylaluminum,
diethylealuminum chloride, and 2-methylpentyldiethylaluminum.
Triethylaluminum is preferred since this compound has produced excellent
results.
The molar ratio of the organometallic compound of the cocatalyst to the
transition metal halide of the first catalyst component is not
particularly critical and can be selected over a relatively broad range.
Generally, the molar ratio of the organometallic compound of the
cocatalyst to the transition metal halide of the first catalyst component
is within a range of about 0.01 to about 1500:1, preferably from 0.01 to
200:1.
In some cases it may be desirable to use a multi-component cocatalyst
system comprising triethylaluminum and either aromatic esters such as
ethylanisate, ethylbenzoate and methyl-p-toluate, etc.; or silanes such as
diphenyl dimethoxysilane, triphenyl ethoxysilane, methyl triethoxysilane,
etc.
The polymerization process according to the present invention can be
conducted in a solution phase process, in the presence or absence of an
inert hydrocarbon diluent, in a particle form process, or in a gas phase
process.
The polymerization process employing the catalysts and cocatalysts as above
described can be performed either batchwise or continuously. In a batch
process, for example, a stirred autoclave is prepared for use by first
purging with an inert gas such as nitrogen and then with a suitable
compound, such as isobutane for example. When the catalyst and cocatalyst
are employed, either can be charged to the reactor first or they can be
charged simultaneously through an entry port under an isobutane purge.
After closing the entry port, hydrogen if used, is added, and then a
diluent, if used, is added to the reactor. The reactor is heated to the
desired reaction temperature, which for polymerizing 4-methyl-1-pentene,
for example, is generally within a range of about 20.degree. C. to about
120.degree. C and the monomer is then admitted and maintained at a partial
pressure within a range of about 0.1 MPa to about 5.0 MPa for best
results. At the end of the designated reaction period, the polymerization
reaction is terminated and the unreacted olefin and diluent can be vented.
The polymer can then be collected as a free-flowing white solid and dried
to obtain the product.
In a continuous process, for example, a suitable reactor such as a loop
reactor can be continuously charged with suitable quantities of solvent or
diluent, catalyst, cocatalyst, polymerizable compounds and hydrogen, if
any, and in any desirable order. The reactor product can be continuously
withdrawn and the polymer recovered as appropriate, generally by flashing
the diluent (solvent) and unreacted monomers and drying the resulting
polymer.
The olefin polymers made with the catalysts of this invention are useful in
preparing articles by conventional polyolefin processing techniques such
as injection molding, rotational molding, and extrusion of film.
The following example will serve to show the present invention in detail by
way of illustration and not by way of limitation.
EXAMPLE
The example compares relative catalyst activity of catalysts treated with
various activating agents with those that have not been so treated.
The first catalyst component was prepared by the following procedure. A
solution of 4.17 g (36.6 mmoles) dibutylmagnesium in 43 mL heptane was
added to 240 mL xylene which contained 12.4 g 4-phenylphenol. The reactor
was heated to 100.degree. C. and held for 1 hour and the mixture was
stirred. The reactor was cooled to room temperature, 2.0 mL TiCl.sub.4
were added to form a solid product in slurry. The slurry was stirred at
room temperature for 1 hour. The reactor was then heated to 100.degree. C.
and held for 1 hour with stirring. The reactor was cooled to room
temperature and allowed to stand overnight. The reactor was then heated to
50.degree. C. and 23 mL ethylaluminum sesquichloride (25 wt. %) were
added. The reactor temperature was maintained at 50.degree. C. for 1 hour
and then the slurry was filtered in a glove box. The brownish-violet solid
was washed with 40 mL of heptane and dried to produce the first catalyst
component. The yield was 22.14 g. Indicated portions of the first catalyst
component without activation, were employed in the polymerization of
4-methyl-1-pentene, Table 1, Runs 101 and 102.
Other portions of the first catalyst component were treated with various
activating agents. Each catalyst was prepared by treating 2.00 g of the
first catalyst component with the activating agent indicated in Table 1,
Runs 103 to 111. The treatment was conducted at 100.degree. C. and the
temperature was held for 1 hour. The thus activated catalyst was filtered
and washed 2 times with ]10 mL heptane and dried.
The catalysts were employed in the polymerization of 4-methyl-1-pantene.
The polymerizations were conducted in a one gallon stirred stainless steel
autoclave. To the clean reactor, 1300 g of liquid 4-methyl-1-pantene
(4MP1) was charged. 8.4 ml of triethylaluminum cocatalyst (15 wt. % in
heptane) were added, followed by a weighed amount of dried catalyst, as
indicated in Table 1. The reactor was sealed and the desired amount of
hydrogen, approximately 25 psig pressure drop over a 325 cc vessel , was
added. The reactor was then brought to about 50.degree. C. and maintained
for about 1 hour. The reactor was then cooled to about 25.degree. C. as
the pressure was vented. The liquid remaining in the reactor was then
siphoned away and the remaining solid polymer was removed from the reactor
and dried.
In the following table, "Activation Treatment" indicates the reagents
employed in treating a 2.00 g portion of the first catalyst component
described above. "Catalyst" is the mg of catalyst employed in the
polymerization. "Activity" is the grams of polymethylpentene (PMP)
produced per gram catalyst per hour.
TABLE 1
______________________________________
Catalyst Activity
Run (mg) g PMP/g .multidot. hr
______________________________________
Activation Treatment - None
101 23.9 300
102 21.3 270
Activation Treatment - 10 mL TiCl.sub.4
103 24.0 7,000
104 20.9 7,300
Activation Treatment - 5 mL TiCl.sub.4,
5 mL SiCl
105 18.6 6,800
106 25.1 7,600
Activation Treatment - 10 mL SiCl.sub.4
107 27.9 3,300
108 21.0 4,300
Activation Treatment - 10 mL TiCl.sub.4,
10 mL TiCl.sub.4 *
109 18.5 8,800
110 11.4 7,600
Activation Treatment - 5 mL
C.sub.6 H.sub.5 SiCl.sub.3, 5 mL TiCl.sub.4
111 27.8 7,000
______________________________________
*added in sequence
Table 1 demonstrates the effectiveness of the activation treatment in
increasing the activity of the catalysts.
While this invention has bean described in detail for the purpose of
illustration, it is not to be construed as limited thereby, but is
intended to cover all changes and modifications within the spirit and
scope thereof.
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